Life history theory links human physical and sexual development to longevity. However, there have been no studies on the association of intellectual development with longevity. This observational study investigates the relationship between the onset of intellectual maturity and lifespan through the life histories of composers and creative writers, whose intellectual development can be gauged through their compositions and writings. In these groups we model the relationship between the age at first creative work, and age at death using multilevel regression, adjusting for sex, date of birth, and nationality. Historical biographical records on 1110 musical composers and 1182 creative writers, born in the period 1400 AD through 1915 AD, were obtained from the Oxford Companion to Music and the Oxford Companion to English Literature. Composers and creative writers lived, respectively 0.16 (p = 0.02) and 0.18 (p < 0.01) years longer for each later year of age at first work. When completion of the first creative work is interpreted as a proxy for the onset of intellectual maturity in composers and creative writers, our findings indicate that a later onset of intellectual maturity is associated with higher longevity.